Z94.12.2 Foundry/Casting

X-RAY. Form of radiant energy with wavelength shorter than that of visible light and with the ability to penetrate materials that absorb or reflect ordinary light. X-rays are usually produced by bombarding a metallic target with electrons in a high vacuum. In nuclear reactions it is customary to refer to photons originating in the nucleus as gamma rays and to those originating in the extranuclear part of the atom as x-rays.